tr4 Wanted - Main Bearing Caps/Crankshaft for TR4 Engine

[rcreweread]

Hi All

 

Has anybody got a set of main bearing caps for a TR4 engine. I acquired an incomplete engine in bits years ago including a good block, but I don't have any main bearing caps to go with it - given the number of blocks which have got trashed over the years, I imagine there must be a lot of lonely main bearing caps lying in dusty sheds/garages and they are not the sort of things which typically wear - can't justify spending a fortune but thought I would ask! If you have the bolts to go with them, even better.

 

I know I will have to get any new caps line bored with the block but I understand this is perfectly doable.

 

The only other bit I am still missing is a crankshaft, so if anyone has one of those going cheap, I might be interested as well - don't mind if it needs a grind, in fact probably prefer that, so long as it's serviceable. Not in a desperate hurry, just thought I would take the opportunity to enquire - be interested to know if there is a target price point for the new ex fergy cranks which are currently being assessed/ sourced ( Roger?)

 

Cheers

 

Rich

[RogerH]

Hi Rich,

sorry Rich no spare crank at the moment. Are you sure you will be able to get 'odd' caps line bored?

 

The drawings for the new crank are on the point of signing off then it is over to the machinist to make sure they talk to the machines.

 

No price set just yet a sit depends on machining costs etc but will be sub-£1000 hopefully nearer £700 but we have to see.

 

You could always install a new tractor crank. It fits and would work for touring etc.

 

Roger

[rcreweread]

Roger

 

Thanks for info re the crank - never thought of using a standard fergy crank - you say it would be OK for touring, but would you have to limit revs?Presumably it would help to have all the reciprocating parts fully balanced but are you aware of anyone who has actually done this?

 

Re the main bearing caps, in answer to your question, " Are you sure you will be able to get 'odd' caps line bored", I've been told that this is perfectly possible, but personally, I don't know - I'm sure there are more learned TRers on here than me who will know and will hopefully post - if it can't be done, then I will have a nice coffee table base!

 

Cheers

Rich

[Lebro]

Using an engine block to support a coffee table top is now out of date - see the new Top Gear !!

 

Bob.

[Alec Pringle]

Hi Rich,

 

whether or not it's possible to get 'odd' caps line bored to fit is an open question - one of those jobs that is easier said than done. Last time I came across this situation (on a more exotic/expensive engine) the machine shop concluded that it was more cost effective to make up bearing caps from scratch than to spend hours trying to make an 'odd' set fit . . . . . and when you think about the individual caps being out of line in different directions, it's not hard to see why . . ..

 

Cheers

 

Alec

[Motorsport Mickey]

Re the line boring the caps, never done it myself (toolroom machinist) but having thought about it I think the caps would have to be reduced in depth by machining the split line and possibly even the block split line being machined, (probably only by 20 or 30 thou)and then the fit assessed to see if mods to the sides of the caps and block needed cutting.

Fit the caps to block and torque up and bore out the required amount (probably less than 10thou) from block and caps to standard crank size, taking the opportunity to "blueprint" the deck face absolutely level to the crank plane through the block. I reckon 8 hours machine time. Obviously the block and caps will have their strength slightly reduced by the material removed but given the "call me Hercules" build of the TR block and bits it wouldn't bother me to take one racing.

 

Mick Richards

Edited March 12, 2017 by Motorsport Mickey

[david ferry]

Hi Rich,

 

Without wishing to be gloomy, I suspect that even if you get hold of a set of main bearing caps for free, I'd have thought that you will probably be better off financially by tracking down a matched set of caps and block. the machining costs are likely to be higher than the cost of a block. If you get a complete engine, the crank may even be useable too!

 

I am in the same position as I have a cracked block which 'donated' it's bearing caps to another capless block. Both of these are set on one side until the point of desperation sets in and these may then get repaired for use in my racecar/spare racecar engine. I suspect that point will never arrive.

 

It's a shame really, but there are, even now, enough complete engines/blocks with caps to make the machining costs not viable - in my experience.

 

Fortunately, your block will make a great doorstop/coffee table/garden planter etc

 

David

[stuart]

Anyone ever tried just swapping in other caps and fitting a set of shells and driving on?

Stuart.

[oldtuckunder]

At last years engine rebuild (whilst on my now hopefully resolved #5 BE failure cause search) I got the machine shop who were doing the crank to also do a line bore check on the 6 block. When I picked it up they said they said it had been fine but they had cleaned .001 out just to make sure it was perfect as they used the same machine to check and bore, and all the effort was in setting it up. I think it cost around £75. Now I know this is different from smacking in a set of random caps and hoping it will machine out OK, but if you have a block and a set of caps it wouldn't be too expensive an exercise to find out, and with a crank and a few new sacrificial shells and some plastigauge you could do a bunch of trial assembly first to see if they were wildly out before even starting.

 

Alan

[Charlie D]

Rich,

 

I’m in the opposite position to you. Over the years I have stripped down several TR engines and never got around to putting them back together.

 

Somehow I’ve lost 2 of the blocks (no, I don’t know how…), and so I do have a set of main caps you can have just for the price of the postage. (Be warned… they are heavy, so postage will not be cheap.)

 

The problem I had when I came to build up the engine I intend to use in my TR was working out which caps came from the good TR block I had.

 

Close inspection of the caps and the block showed a hand stamped number, which at first thought was random, but then I realized that one set of caps had the same number as the block I had.

 

Maybe this is well known, if not I’ve taken a photo to show what the markings look like.

 

PM me if you are interested in the caps.

 

 

Charlie D.

[cvtrian]

Hi All

 

The only other bit I am still missing is a crankshaft, so if anyone has one of those going cheap, I might be interested as well - don't mind if it needs a grind, in fact probably prefer that, so long as it's serviceable. Not in a desperate hurry, just thought I would take the opportunity to enquire - be interested to know if there is a target price point for the new ex fergy cranks which are currently being assessed/ sourced ( Roger?)

 

Cheers

 

Rich

 

Hi Rich, and everyone else

The new cranks will not be ex fergy tractor cranks, they will be cast and machined with cross drilled galleries to TR spec. specifically for a TR rather than a Fergy crank adapted to fit.

 

The 3D scanning and cnc files have been prepared, we just need to ensure the machinery speaks the same language when the files are transferred to the factory.

 

One of the two prototype cranks produced to date is fitted in MVC575, Roger has tested the other over many thousands of miles, and MOSS have been an excellent and willing particpant as a supplier, it's their money at risk along with that of the SDF.

 

Hope that clarifies what we have been doing lately

Regards

Ian

 

PS I have just seen that Roger has provided a more detailed update on a separate thread ---- http://www.tr-register.co.uk/forums/index.php?/topic/61371-fergy-crank-in-a-tr4/

Edited March 13, 2017 by cvtrian

[rcreweread]

Hi Rich,

 

Without wishing to be gloomy, I suspect that even if you get hold of a set of main bearing caps for free, I'd have thought that you will probably be better off financially by tracking down a matched set of caps and block. the machining costs are likely to be higher than the cost of a block. If you get a complete engine, the crank may even be useable too!

 

I am in the same position as I have a cracked block which 'donated' it's bearing caps to another capless block. Both of these are set on one side until the point of desperation sets in and these may then get repaired for use in my racecar/spare racecar engine. I suspect that point will never arrive.

 

It's a shame really, but there are, even now, enough complete engines/blocks with caps to make the machining costs not viable - in my experience.

 

Fortunately, your block will make a great doorstop/coffee table/garden planter etc

 

David

David - what you say makes perfect sense except that the engine block in question is relevant to a project I'm doing, so if at all possible, I would like to use it, and hopefully Charlies offer will assist in that direction.

 

I also cant bear to see anything wasted, and if I bought a whole engine, it would seem pointless splitting it, so in my mind I would be no further forward! Daft I know, but us humans are a strange bunch, sometimes!

 

Charlie - I will be sending you a PM shortly

 

Cheers

 

Rich

[RogerH]

Hi Rich,

I'm thinking in very strange directions now.

If you must retain the block - and why not, and the new caps are not ideal, ask the machine shop if it is possible to add a backing spacer to the bearing shell within the cap either machined or fabricated. I don;t know if it is possible as the shell locating tang would then have a problem.

 

As Mick pointed out this will weaken the cap slightly but may still be strong enough.

 

Roger

[stuart]

I do hope they get a lot use out of the new crank in MVC as that was supposed to go in mine!

Stuart.

[mjdearing]

Hello Rich nobody has mentioned Vanguard cranks ? many years ago i fitted one in my TR4 cant remember any fitting problems and i thrashed the danglies off that motor,think it also had a split rear seal as standard but Rodger will probably know more on this,so if you want to go this route get in touch. Martin.

[RogerH]

Hi Martin,

I have no knowledge of Vanguard cranks but they sound similar to the TRactor crank.

 

Did the Vanguard have the cross drilled big-ends?

If it did not, then perhaps the Vanguards may have a source of new cranks. Thank you Fergy.

 

Roger

[stuart]

Hi Martin,

I have no knowledge of Vanguard cranks but they sound similar to the TRactor crank.

 

Did the Vanguard have the cross drilled big-ends?

If it did not, then perhaps the Vanguards may have a source of new cranks. Thank you Fergy.

 

Roger

I think the difference is the cross drilling that was brought in for the TR.

Stuart.

[Charlie D]

Roger,

 

 

A few years ago I bought a Vanguard engine foolishly thinking that the block was the same as the TR.

 

Attached is picture of one of the bearings, with screwdrivers poked in to show where the holes go to.

 

Maybe useful for you database of Standard Triumph cranks. (I think it was from a 1960 Vanguard.)

 

The engine was only £15, so if the crank is OK, it's a cheap alternative. (I bet there are hundreds of Vanguards sitting in farmer's sheds.)

 

Charlie D

[RogerH]

Hi Charlie,

that complicates things.

The red handle screwdriver is going in at TDC - this is correct for the TRactor and very early TR's (no cross drilling)

 

However your other two screwdrivers are going in where the cross drilling should be but at an angle.

The cross drilling went straight across the diameter of the journal and required the additional oilway where the 5/16 plugs are on the web.

 

Roger

[Charlie D]

Roger,

 

I guess that means that oil is still getting to the same places as it does with the “Conventionally” cross drilled TR crank.

 

Makes you wonder why it was done in 2 different ways to achieve the same end result, unless the flow is better doing it the TR way.

 

But if that were the case, you would think that ALL the cranks would have been done the same way, just for manufacturing efficiency.

 

 

A bit of a mystery…

 

Charlie D.

[RogerH]

Hi Charlie,

Here is a little history that I think is correct.

The TRactor crank and very early TR2 has a straight drilling from the main bearing to the big-end and breaks out at TDC in a 1/4" diameter oilway.

This works for normal use.

However somebody must have found or calculated that with the TR engine (5000+rpm) the centrifugal forces threw the oil out too quickly - perhaps the pump couldn't keep up!!

 

So the cross drilled crank was born.

This has a drilling from the main bearing ALMOST to the BE TDC position but does NOT breakout.

This drilling does not intersect the cross driling so an extra 'dog leg' oil way is added from the corner of the web to the cross drilling - this intersects all the oilways

At TDC there is a 5/64" hole connecting to the cross drilling. Why? I do not know.

 

The two new proto-types had another version.

There is only one drilling - it goes in the opposite direction. From the corner of the web through the BE cross drilling and down to the Main Bearing

The MB drilling is moved around 90' - so it is horizontal rather than vertical.

No dog leg drilling. But it does have the 5/64" at TDC.

This is a much better design as there are less holes/oilways etc.

 

The new cranks will have ALL the normal oilways as per a typical TR4 engine.

 

How many other designs are there

 

Roger

[Charlie D]

Thank you for the explanations Roger.

 

 

Like you say:

“How many other designs are there”

 

I bet there were loads of discussions/disagreements back in the design office in Coventry.

Pity most of the people who were there at the time are no longer with us.

 

Tales that could be told... Lost forever...

 

Charlie D

[Alec Pringle]

Vanguard cranks evolved through the years . . . . . the original design was superseded by the cross-drilled TR spec crankshaft, part no 301815, during Vanguard Phase III production.

 

Vanguards post V323401 and Sportsmen post 503 should have the pukka TR crank . . . . . and earlier engines subjected to crank replacement will probably have had fitted 301815 too. Ensign De Luxe and Atlas engines should also be fitted with the 301815 cranks which continued as TR spec from TR2 through to the last TR4A.

 

Wet liner main bearings, incidentally, were a constant regardless of crank or application . . . . . unlike big end bearings, which varied considerably over the years and applications.

 

Cheers

 

Alec

[Dick]

Hi Rich,

I have a set of main bearing caps if you are still looking.

Dick

[rcreweread]

Dick - have sent you a PM

 

cheers

 

Rich